Implementation of the methodology QuEChERS in the residual pesticide analysis in white corn (Zea mays)

Abstract

The use of pesticides on maize crops during and after harvest constitutes a serious health and environmental risk if its prevalence remains during the consumption line. Therefore, the proper determination of the residues of such substances is critical for minimizing the negative impact of pesticides on health and quality of agricultural products. The aim of this study was to evaluate the multiresidual extraction methodology QuEChERS (“Quick, Easy, Cheap, Effective, Rugged, Safe”) as an economic alternative with easy implementation for the analysis of 10 pesticides in floury white corn (Zea mays). Two variants of this method were tested: the original non-buffered method and the official method AOAC 2007.01 with acetate buffer. Analyzes were carried out by gas chromatography with electron capture detector (GC-ECD). Co-extractives percentage and moisture in the final extract were compared, and a check in terms of accuracy, linearity, accuracy, and sensitivity matrix effect was made. Implementation of the original method permitted to obtain cleaner extracts and more consistent and appropriate (overall average between 71,4 – 111,6% with coefficients of variation less than 9,2%) recovery percentages. Additionally, linearity (r> 0,9892) and limits of detection and quantification below the maximum residue limits established by the European Commission (10 to 50 mg kg-1) were also obtained, which makes this method a good choice to routinely quantify the residual effect of the assessed pesticides in the matrix of work.

Keywords

• pesticides
• multiresidue extraction
• corn
• quechers
• gc-ecd